Steam-generator.



F. P. RUDDER.

STEAM GENERATOR.

APPLICATION FILED JUNE 1, 1912.

1,102,959. Patented July 7, 1914 W ITNESSES INVENTOR "unite:

orurcn.

FRANK 3953C?" RUEWFJEFV, GF DERBY, ENGLAND, ASGIGNOR T GEORGE FLETCHERAND QGM'E'LNY LIMITED, OF LITGHURCH, DERBY, ENGLAND.

STEAIiI GENEBATOR.

Specification of Letters Patent.

Application filed Eune l. 1512. serial No. 709,996.'

To all whom it may (Gi li/(7171,,

Be it known that 11, FRANK Pnucr Runoicn. u rllilllsli subject, residingat Derby, county of Derby, gland, have invented certain n w and usetollrnprovenient in Stenni-Uenerutoro, of which the following is a .c,

This invention rel-sites to steam gomwM-nrc mom articularly adapted foruse in cane 1 sugar factories Where large reserves of steam are requiredand the situations of which enerally present exceptional trunsport diculties. 111 such factories, the fuel is principally the refuse fiberfrom the cane contuining a high percentage of moisture,

and generally of achnrncter that necessitates its being gasified andburnt in a fun none at some distance from the boiler; the products ofcombustion being led from a 29 combustion chamber and passed over theheating surface of the boiler the transfer offbeat to the Water beingalmost entirely by means of conduotion. Therefore it will be readilyappreciated that the type of stear'n $5 generator most suitable to theseconditions,

will be one wherein the gases/are divided and broken up into runnystreams of flow, and Eli ibuted evenly over the heating surfuoe, no pl l89 water,

water tube boilers on the market, embody fully, such advantages, but itis generally admitted, that their thermal reserve, 2'. e.,

their water and steam carrying capacity is' very lirnieelencl such nreserve is of the utmost importance H1 a sugar rectory where the qualityof the fuel varies from hour to hour and even the supply may be checkedchoked with. the line and light ash, carriedin suspension, with the usesfrom the fiber to fuel; and also the ems or the tubes fare.

with rapid circulation ofthe fiievmel. oi the well known types of burntaway at the firing end of the boiler.

If fired under the shell, the eflic'ienc'y is relatively poor, and theshell is subjected to serious local strains which almost always resultin grooving at the seams nearest the combustion chamber, especiallywhere effieientfurnaces and consequent. high temperatlrcs in present.

(b). Large units (for which there is a natural demand with largefactories) for 66 high working pressures (which is also now universallyspecified), become ver heavy and difiicult of transport. In fact, withthis type of boiler the heating Surface of single units is practicallylimited to from 10 2500 to 3000 square 'feet, whereas units having twicethis amount of surface are reguv larly desirable.

For these and other reasons; the water tube type of boiler has been usedin ma-nyfib factories of recent years, but with these the insufficiencyof thermal reserve has a-t,once been felt, and to compensate for this itis often necessar to carry-lend have under steam, more boiler bower thanisjictually re quired, to avoid serious preesure fluctuations inordinary orking. Thi is a disadv'nntuge of considerable importance, thethen not only are the capital charges increacedfbut the active heatingSurface generally is beingas used inefiiciently. Steam generators havealso been proposed in which a scree of water tubes forming part of themaincircubiting symcm are placed between the-futnace and the fire tubesof boiler; 5 1

My invention consists essentially of a com"- posite steam generatorcomprising Mi external furnace, a fire tube Holler-and d wit-- ter tubeboiler the tubes of which latter are interposed between the furnaceand'the five tubes so as to form a screen, the Water tube boiler belugaseparate unit with water and steam drums formin an independentcirculation and being a so connected by pipes to the fire tube boiler. Asuperlreatur may also be placed between the water tube boiler and thefire tube boiler.

The invention will be fully described with reference to the"accompanying drawing which shows a longitudinal section of the steamgenerator. The composite steam generator IBEMB 'in two sections a watertube section 'and a tubular shell-section B. The tubes a of the watertube-soctionform a i screen for, the tubular shelliwh ieh receives lbsthe gases after they have passed over the said tubes at. The water tubesection comprises a steam drum C and a water drum D connected b theafore-mentioned water tubes a, which latter are arranged in-inclined orupright position, an independent circulation takin place through thesetubes. The tubular sheli section comprises a unit of a tubular generatorB of ordinary construction without a fire box or grate. The water tubes(1 take up the highest heat from the gases and protect the shell of thetubular generator B from the action of the very hottest gases. Thetubular unit B is connected with the drums C and D by water circulatingtubes 0 and d and with the steam s ace of. the drum, C by a steam pipe 0the steam bein preferably drawn off from the unit B by t e steam pipeI).

' Baflie plates E of metal or refractory material are placed behind thelower portion of the water tube screen to direct the flow of gasesupward so as to traverse the water tubes a and give up a considerableportion of their heat thereto before passing to the ire tubes of theshell section B. A steam superheater G when employed is placed at ornear the top of the water tube screen A between the drum C and the shellB so that the ases. impinge thereon before entering the re tubes. Thesuperheater tubes may ,bearranged as shown or in any other suit ablemanner. For large installations in order to reduce the weight and sizefor trans fer of heat results and the temperature of the gases isreduced to a moderate temperature before'being passed to the tubular.shell section of the holler, In passing through the screen any ashcarried in suspension is separated from the gases and deposited in theash pit or in ash pockets provided for the purpose.

(5). 'An improved lengthwise circulation will be set up in the shellsection due to the rush of water that will take place from tho drum C ofthe water tubesection to the shell section, through the circulatingtubes 0.

(a). A steam and water reserve almost double that of any type of watertube boiler is obtained.

(d). Large installations for the highestpressures may be arranged,without any dif ficulty of transport arising from great Weight of anypart. In the largest installa tion the shell sections or units B neednot be more than (3 ft. diameter by 10 ft. long, and therefore, the useof very heavy plates for shells and ends would be avoided,

(c). The water tube heating surface section may be added to existingcylindrical boilers, thus forming them into larger and more eflicientinstallations at relativcly'sniull cost.

What I claim as my invention and desire to protect by Letters Patentis 1. In a steam generator, the combination with a furnace having a flueleading from the combustion cl'ianiber thereof, of a fire tube boilerunit having its tubes connected to receive the heated from said flue, awater tube boiler unit interposed between the fire tube boiler unit andsaid combustion chamber, the tubes of the water tube boiler unitextending transversely across said flue, and means for causing theheated gases in the flue to How along the tubes of the water tube boilerunit and thence transversely between such tubes and for protectingthc'shcll of the the tube boiler unit.

52. In a steam generator, the combination with a furnace having a flueleading from the combustion chamber thereof, of a fire tubc boiler unithaving; its tubes communicating with said flue, an upright water tubeboiler unit interposed between the fire tube boiler unit and saidcombustion chamber and having its tubes extending transversely acrosssaid flue, water circulating connections between the lower and upperportions of the water tube boiler unit and the fire tubc boiler unit,and means for dir, g the gases along the tubes of the water tube boilerunit and thence transversely between said tubes and into the tubes ofthe lire tube boiler unit and for protecting the shell of the latterunit.

3. In a steam generator, the combination with a furnace having a fineleading from the combustion chamber thereof, 0i. a tire tube boiler unithaving its tubes communi eating with said flue, an upright Water tubeboiler unit interposed between the fire tube boiler unit and saidcombustion chamber and having its tubes cxtending transversely acrosssaid flue, the water tube boiler unit having upper and lower watercirculating drums, .water circulating connections between the upper andlower drums of the Water tube boiler unit and the water space of thefire tubc boiler, a steam connection between the upper drum and thesteam space of the fire tube boiler unit. and a steam outlet pipeleading from the fire tube boiler unit.

4. A steam generator comprising in its construction, three separateunits: an extcr nu] furnace, a water tube unit with inde- 5 and thesteam space thereo and a steam superheater placed between the water tubeunit and the fire tube unit.

In testimony whereof I have hereunto set my hand in presence of twosubscribing wxtnesses this 18th day of May 1912.

FRANK PERCY RUDDER.

Witnesses:

- C. K. Eonowne,

W. H. Bmcxemm.

